ACID- AND CORROSION-RESISTANT STEEL FOR PIPELINE WITH LARGE WALL THICKNESS AND METHOD OF PRODUCTION THEREOF Russian patent published in 2022 - IPC C21C7/04 C21C7/64 C21C7/68 C21C7/76 C21C7/10 C22C38/50 C22C38/28 C21D8/10 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to acid and corrosion resistant steel for making thick-walled pipeline. Steel contains the following components in wt. %: C: 0.01–0.02; Si: 0.10–0.35; Mn: 0.9–1.40; P≤0.012; S≤0.0010; Nb: 0.020–0.070; Ti: 0.006–0.020; Ni≤0.30; Mo: 0.10–0.30; Cr: 0.10–0.30; Cu: 0.10–0.30; Al: 0.015–0.050; Ca: 0.0005–0.0040; wherein the residue is Fe and impurities. In the process of steel production, the cast billet is subjected to austenitization at temperature of 1110–1120 °C. Water temperature at the inlet during rolling is 790–800 °C, and ultra-fast cooling is used for cooling to 280–300 °C to obtain an ultra-fine grain structure with a core less than 30 mcm.

EFFECT: higher resistance to acids and corrosion, including in the presence of hydrogen atoms.

4 cl, 2 dwg, 3 tbl